Sealing disc for crown closures



United States Patent SEALING DISC FOR CROWN CLOSURES 4 Claims, 4 DrawingFigs.

U.S. Cl... Int. Cl Field of Search Primary ExaminerGeorge T. HallAtt0rneyMcGlew and Toren ABSTRACT: A sealing disc for use with acorrugated type cap closure for a bottle is made of nonrigid syntheticresin and has a thin, filmlike flange on its periphery. Projections areformed on the disc near its periphery for closely contacting the edge ofthe bottle opening and the adjacent surface of the cap closure.Additional annular projections are formed in the central region of thedisc for contacting the inner surface of the cap Upon capping thebottle, the filmlike flange is pressed into the internal recesses formedin the corrugated side portions of the cap and assists in sealing thebottle.

Patented Nov. 17, 1970 3,540,611

INVENTOR. I A n v lllsmkn Ma Ma l amw

SEALING DISC FOR CROWN CLOSURES BACKGROUND OF THE INVENTION It iswell-known to use a sealing disc for bottle cap or crown closures. whichare made of a synthetic resin. These discs are provided, in the mainbody thereof, with the following: an inner annular projection or rimadapted to press the inner peripheral wall ofa bottle mouth and locatedon the upper and lower surfaces of the boundary between the peripheralportion of the bottle top and the central portion placed over theopening of the bottle mouth, an outer annular projection adapted topress the external peripheral wall of the bottle mouth on upper andlowersurfaces of said periphery, annular grooves formed symmetrically onupper and lower surfaces, respectively, on a portion where the baseportion of the outer annular projection and the peripheral portioncontact, inclined surfaces slopiiig down outwardly formed on upper andlower surfaces of the outer annular projection, and the inside diameterof the main portion of up to the neck portion of the outer annularprojectionbeing made substantially equal to the inside diameter of thecap or crown closure, whereby the outer annular projection is made tocontact against the inner peripheral wall ofthe crown closure by bendingat the annular grooves.

With the above described sealing disc for crown closures, however, thedegree of intrusion or flow of the outer annular projection into theinternal recesses formed by the corrugations on the skirt portion of thecrown closure is incomplete, and since the central portion of the discis in contact with the inner surface of the top plate of the crownclosure, there has been the disadvantage that the sealing effect wasprevented because of the deformation due to the pressure within thebottle.

The sealing disc for a crown closure according to the present inventionis excellent in its sealing effect due to a construction that includes athin, filmlike flange or projection extending laterally from theperiphery of the circular main body which is pressed into the recessesformed on the inside of the corrugated wall of the crown skirt so thatno gap is formed therebetween, and concentric annular projectionslocated in the central portion of the disc and arranged to contact theinner surface of the top plate of the crown closure for preventing thedeformation of the sealing disc due to the pressure inside the bottle.

SUMMARY OF THE INVENTION The object of the present invention is toprovide a sealing disc for a crown closure which can be fitted firmlyinto the cap body without the fear of being detached, the crown cap,fitted with the disc according to the present invention, being mounted'on the mouth of a bottle, the disc in the crown cap will not bedeformed, during the use, by the pressure within the bottle, thus thesealing effect thereofis much improved.

According to the invention, in mounting the sealing disc in the metalcrown cap, the thin, filmlike flange is made to contact the inside ofthe corrugated skirt portion of the crown body by bending at the baseportion of the filmlike flange, and the main body ofthe disc, which ismade ofsynthetic resin, according to the present invention is fittedclosely inside the crown cap by its elasticity.

In accordance with the present invention, the main body of the disc forthe crown cap is maintained flat because the top portions of theconcentric projections press against the top plate of the crown andthis, maintains the exact position of the disc inside the crown body.

Furthermore, in accordance with the present invention, the filmlikeflange portion is pressed into the interior recesses in the corrugatedwall formed on the skirt portion of the crown body, and this engagementmaintains the main body of the disc firmly and'immovably within thecrown body.

When a crown closure fitted with the disc, according to the presentinvention, is capped on the mouth ofa bottle, with the pressing contactof the upper side of the inner annular projection of the disc on theinner surface of the top plate of the crown cap, the lower side of theinner annular projection is pressed against the inner shoulder of thebottle mouth, and at the same-time the upper side of the outer annularprojection or rim portion is pressed against the inner shoulder of thecap body, and the lower side of the rim is pressed against the outershoulder of the bottle mouth, the lower side of the inner annularprojection and the lower side of the rim portion are fitted closely onthe edge portion of the bottle mouth, thus completely sealing thebottle.

With the disc for a crown closure according to the present invention,the top portions of the concentric annular projections in the centralportion of the disc press against the inner surface of the top plate ofthe crown body and support the central portion securely inside the innerannular projection, so that any deformation of the central portionitself due to the pressure inside the bottle can be prevented, and nogap between the annular projection and the inner shoulder portion of thebottle mouth is produced, and thus extremely excellent sealing can bemaintained.

According to the present invention, the mechanical strength at thecentral portion of the disc is increased by the provision of theconcentric annular projections, and during the use of I the crownclosure fitted with the disc of the present invention on the bottlemouth, the disc of the crown cap shows a favorable resistance againstthe pressure produced inside the bottle, and no deformation such asextension will ever be produced.

With the disc of a crown closure according to the present invention, theradial tension of the central portion is essentially supported by theconcentric annular projections, the tension being transmitted uniformlyto the annular projection, the deformation of the annular projection canbe checked favorably and the sealing effect is maintained positively.

Furthermore, a disc of the crown closure of the present invention givesa favorable result although a nonrigid synthetic resin material is usedin molding-the disc. That is, in the cooling and setting course duringthe molding of the disc, the thin portions of the disc cool down and setprevious to the thick, projecting portions of the disc which are stillin a molten state, and the deformation of said thin portions of the discliable to be produced by their quick cooling is prevented by the thickportion where the heat capacity is greater, thus an appropriate plasticdisc having no internal strain, and therefore no twisting nor flexure isformed.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a plan view of the disc for acrown closure according to the present invention;

FIG. 2 is a cross-sectional view along the line [1-1] of FIG. 1; FIG. 3is a cross-sectional view of the disc according to the present inventionshowing the statein which the disc is inserted in a crown closure; and

FIG. 4 is a cross-sectional view of the disc showing the crown closurewhen the latter is capped on the mouth ofa bottle.

DESCRIPTION OF THE PREFERRED EMBODIMENT The invention will now bedescribedwith an embodiment referring to the appended drawings.

A circular disc made of a nonrigid synthetic resin comprises a rimportion 2, 2a and an annular projection 3, 3a each projecting from anopposite side of the main body 1, a thin, filmlike flange portion 5extends laterally in a horizontal plane from; and circumferentiallyabout the central portion of the vertical peripheral wall 4 of the mainbody 1. A pair of concentric annular projections 7, 7a, 8, Sa extendfrom each face of the central portion 6 of the disc located inwardlyfrom the annular projection 3, 3a and an annular groove 9, 9a isprovided on each surface of the base portion of the rim 2, 2a adjacentthe annular projection 3, 3a.

The annular rim portion 2, 2a, the annular projection 3, 3a, theconcentric annular projections 7, 7a, 8, 8a and the annular groove 9, 9aare all formed symmetrically on the upper and lower surfaces of the mainbody 1.

The rim portion 2, 2a is formed corresponding to the'outer shoulderportion 10a of the mouth 10 of the bottle, see FIG..4, and theannular-projection 3, 3a is formed corresponding to the inner shoulderportion 10b of the bottle mouth 10, and inclined faces 3,,g slopingtowards the rim 2, 2a are formed from the top portions of the annularprojection 3, 3a. The thin, filmlike flange is made to contact the innerand upper portions of the corrugated wall formed on the skirt portion ofthe crown body 11, and is formed so as to be pressed into the recessedportions Ila inside the corrugated wall. The top portions of theconcentric annular projections 7, 7a, 8, 8a and the annular projection3, 3a are each made to have a height which when the disc is inserted inthe crown cap, each of the top portions contacts the top plate 11b ofthe cap body 11 as shown in FIG. 3.

A preferable shape and dimensions for the .disc for a crown closureaccording to the present invention are as follows: when the diameter 1(see FIG. 2) of the outer peripheral wall 4 of the main body 1 is 27mm., it is proper to for the thickness d of the main body 1 to be 0.2 to1 mm., the thickness d of the flange 5 to be one-half to one-third ofthe thickness d, of the main body 1, the width w of the flange 5 to beone-fiftieth to one-tenth of the diameter of outer peripheral wallportion 4 of the main body 1, the height h, from the flat surface of thecentral portion 6 of the main body 1 to the top portion of the annularprojection 3, 3a to be 0.5 to 1 mm., the height h from the flat surfaceat the central portion of the main body 1 to the top of the concentricprojections 7, 7a, 8, 8a to be 0.2 to I mm., and the width W of each ofthe concentric projections to be 0.4 to 2 mm., respectively.

The disc for a crown closure according to the present invention beingthus constructed, in inserting the disc into the crown body 11, thefilmlike flange 5 bends itself at the base portion thereof so as to bepressed into the recessed portions Ila of the corrugated wall formed onthe skirt portion of the crown body 11, and the main body of the discdue to its elasticity is inserted into engagement with the crown body11.

Since the top portions of the concentric projections 7, 8 or those ofthe concentric projections 7a, 8a (when the disc is used upside-down)are made to contact with the inner surface of the top plate 11b of thecrown body 11, the main body 1 of the disc is maintained flat, and isinserted and engaged in the correct position.

When the crown closure fitted with the disc is capped on the mouth of abottle, the filmlike flange portion 5 is pressed and made to contact theupper portion of the corrugated wall formed in the skirt portion ofthecrown body 11, and the parts thereof are pressed into the recesses 11aof the corrugated wall, so that the main body 1 of the disc is heldfirmly and immovably within the crown cap 11, and at the same time sincethe flange portion 5 is deformed within the recesses 11a, and no gap isallowed to form therebetween. When fitting the crown closure includingthe disc on the mouth 10 of a bottle, by the deformation of the annularprojection 3 when it is pressed against the inner surface of the topplate 11b of the crown body'l l, the annular projection 3a of theopposite side is pressed against the inner shoulder 10b of the bottlemouth 10, and at the same time, the rim portion 2 is pressed by theinner shoulder of the crown body 11, so that the rim portion 2a at theopposite side is pressed against the outer shoulder portion 10a of thebottle mouth 10, closing the bottle completely.

Since the top portions of the concentric projection 7, 8 contact withthe inner surface of the top plate 11b of the crown body 11, and supportthe central portion 6 located inside the annular projection 3, 3a, thedeformation of the central portion 6 itself due to the pressure insidethe bottle can be prevented, and no gap is formed between the annularprojection 3a and the inner shoulder portion of the bottle mouth 10,thus maintaining an extremely complete sealing effect.

The grooves 9, 9a assist the deformation of the rim portion 2, 2a andthe annular projections 3, 3a to fit closely on the outer shoulder 10aand the inner shoulder 10b of the bottle mouth The (C for a crownclosure according to the present invention may be fitted closely insidethe crown body without any fear of it'falling out, and when the crownclosure fitted with the disc is capped on the bottle mouth, no gap isformed between the edge of the bottle mouth and the crown body, a closeand complete sealing effect is maintained, and together therewith, anextremely large resistance against pressure may also be formed.

In this embodiment, there is shown two concentric annular projections,but it is to be understood that, for example, one or three or more ofthe concentric projections may also be provided.

I claim:

1. A sealing disc adapted to be inserted into a crown closure forsealing the mouth of a bottle, the crown closure having a corrugatedskirt portion arranged to extend downwardly about the periphery of thebottle at its mouth, the sealing disc being formed of a nonrigidsynthetic resin and comprising a flat circular main body having a firstsurface and an oppositely facing second surface with the first andsecond surfaces being symmetrically shaped, a rim portion extendingcontinuously about the circumferential periphery of said main body andextending generally perpendicularly outwardly from the first and secondsurfaces of said main body, said rim having a radially outwardlydirected circumferentially extending peripheral surface extendingtransversely of the plane of said main body, a filmlike flange extendingradially outwardly from the peripheral surface of said rim in generallycoplanar relationship with said main body, an outer annular projectionextending generally perpendicularly outwardly from the first and secondsurfaces of said main body and being spaced inwardly from said rimportion thereon, the radially outer surfaces of said outer annularprojection located perpendicularly outward from each of the first andsecond surfaces of said main body sloping outwardly toward said rimportion and intersecting the first and second surfaces at an obliqueangle to the plane of said main body and being arranged to form asurface adapted to conform to the top surface of the bottle encirclingthe opening to be sealed by the combination of the crown closure andsaid sealing disc, an annular groove being cut into each of the firstand second surfaces of said body between said rim portion and said outerannular projection and at least one inner annular projection extendinggenerally perpendicularly outwardly from the first and second surfacesof said main body and being spaced inwardly from said outer annularprojection. whereby when the disc is inserted into the crown closuresaid filmlike flangeis pressed into the recessed portions formed by thecorrugated skirt portion and forms a seal therewith for securing thedisc within the crown closure and said inner and outer projectionsextending from the first surface of said main body into contactingengagement with the inner surface of the crown closure which is arrangedto span the mouth of the bottle and when the crown closure and saidsealing disc are pressed onto the mouth of the bottle said rim portionextending from the second surface of said main body being in sealingcontact with the outer periphery of the bottle at its mouth and saidouter annular projection extending outwardly from the second surface ofsaid main body in sealing contact with the inner periphery of the bottleat its mouth.

2. A sealing disc, as set forth in claim I, wherein said filmlike flangehaving a thickness about one-third to one-half the thickness of saidmain body.

3. A sealing disc, as set forth in claim 2, wherein said flange having adimension in the radial direction of between one-fiftieth to one-tenthof the diameter of said main body portion.

4. A sealing disc, as set forth in claim 1, wherein the dimension ofsaid inner and outer annular projections extending from the first andsecond surfaces of said main body being substantially the same and beinggreater than the dimension of said rim portion from said first andsecond surfaces of said main body.

